Collet chuck



Feb. 12, 1952 BI DENZLER 2,585,747

COLLET CHUCK Filed April 12. 1949 IN VEN TOR. Em/MLD ZZL'NZLEH BY KMA/ ATrR/VEY Patented Feb. l2, 1952 COLLET CHUCK I e Berthold Denzler, Chicago, Ill., assignor ofonehalf to Filip Brandhandler, Chicago, Ill.

Application April'12, 1949, Serial No. 87,007

This invention relates chuck. f

One of the objects vof my invention is to provide a collet chuck which is simple in construction, eflicientv in operation,durable in service, and which can be economically manufactured.

Another object of my inventionr is to provide acollet chuck Iin which adjustment of the collet opening may be easily and readily made without disassembly or demounting of the chuck.

Other objects Aand advantages of my invention will beapparent during the course of the follow-f ing description.

In the accompanying drawing forming. a part of this specicationr and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a. longitudinal cross-sectional View partially in elevation' of a collet chuck embodying my invention;

Fig. 2 is a cross-sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is an elevational view on a reduced scale showing the parts in the dotted line position of Fig. 1.

Referring to the drawing, the numeral 5 designates a chuck body having a reduced forward portion 6 and an enlarged rearward portion 1. The portion 6 is provided with an axial bore 8 terminating in a tapered mouth portion 9 which is threaded exteriorly as at II. The rearward portion 1 is provided with an enlarged axial bore I2 which is threaded as at I3. The body 5 iS provided with diametrically opposed slots I4 which extend through portions 6 and 1 thereof. A pair of levers IB, each received in a slot I4, is mounted on pivots I1 secured in the body portion 1. The said levers have cam surfaces I8 and rounded terminal portions 2I. A transverse slot is provided in the portion 1 for a purpose as will be hereinafter described.

Received within the bore 8 and adapted for sliding movement therein is a collet 22 having an axial bore 23. 'I'he collet is rendered radially expansible and .contractible by providing a plurality of slots 24. The head 26 of-the collet is provided with a tapered circumferential surface 21 which cooperates with the tapered mouth portion 9 to effect contraction of the collet jaws. A longitudinal slot 28 on the collet cooperates with a pin .29 extending inwardly of the bore 8 to prevent vrotation of the collet 22 relative to the body 5, but permitting relative axial movement therebetween. The rearward end of the collet is threaded as at 3 I- an improved Vcollet' 1 Claim.y (Cl. 279-51).

The'collet 22is retained in position bya collar 32 in threaded engagement with the threaded end 3I of the collet, the said collar being .prefer-i I ably Vprovidedv with a vknurled circumferential surface. As .is seen, the collar 32 is in registering alinement with the slot 2li and one face of the collar 'is engaged by the cam surfaces I8 of levers I6.

The chuck is adapted for mounting on a driving spindle or shaft by means of member 33 which is inthreaded engagement with the chuck body 5, the Jmember 33 being yprovided with Ma bore 34 to receive the drivingshaft anda set screw l36 to secure the collet on a shaft. Alspring 31 abutting the member 33 and the collar 32 is under compression and constantly tends 'tov thrust thev collar 32 and, therefore,'the collet 22 in an-outf ward direction to relax the grip of the collet onl the object being held. Locking means, here a set screw 38, is provided'to prevent disengagement of the member- 33 from the body V5, the said set screw being received in a threaded opening the axis of which is located on the line of abutment between the body 5 and the member 33 so that one-half of the opening is in the member 33 and the other one-half in the body 5.

The levers I6 are actuated by a sleeve 39 mounted on and slidably axially of the body 5. The sleeve includes an annular member 4I, rotatably supported therein, and a collar 42 in threaded engagement with the sleeve end for retaining said member in position. The member 4I is provided with conical and cylindrical surfaces 43 and 44 respectively, which act in the nature of a cam cooperating with the terminal portions 2I of the levers I6 to rock said levers on their pivots when the sleeve is moved axially causing the cam surfaces I8 to act against the collar 32. The rearward end of the sleeve is provided with one or more recesses 46 for a purpose as will be hereinafter explained. v

A threaded cap 41 having a central aperture is carried on the end of the body portion 6 and serves as a stop to limit movement of the sleeve 39 and serves also as a cover over the mouth of the collet 22 to prevent the ingress of dirt or other particles which may affect the smooth operation of the chuck.

The operation of my improved collet chuck should be apparent from the foregoing description butl briefly stated it is as follows:

Without stopping the rotation of the driving shaft on which the chuck is mounted, the sleevev 39 is moved to the dotted line position shown in Fig. 1. In this position the collet jaws are in 3 expanded or relaxed condition and a tool or other object to be gripped is inserted in the bore 23 of the collet. To effect the gripping of the tool or object, the sleeve 39 is moved to the full line position shown in Figyl, causing the 'terminalv portions 2l of the levers I6 to cooperate with the conical surface 43 of the sleeve 39 thereby causing the levers I6 tomove inwardly ofthe slots I4 to retract the'fcolletE to grip the' toolor Object. When the chuck is in operating positionthe terminal portions 2| of the levers I6 bear against the cylindrical surface 44 of the sleeve which locks the chuck in position when gripping:the

tool. Y Y Y While a collet is generally vdesignedfto-accommodate a particular size of tool "shankfrequently variations in the sizes of the;Shanks;.rtecpeiireV adjustment of the collet opening in order to'effect proper gripping of the tool shank.v )Err-my i improved chuck such adjustment may be made very-.readilyawithoutzdisassembling or demountingr :itne chuck; To make, f an adjustment., the 'sleeve 213 -ii's-r movedgto the` position: slm-wn in Eig;- 'andithenis rotatecito alinefa slet 46 thereof su'cliaas, afpick .orsscrew drivergmayf-thenwbe in- Yserte'd imstheslet :Mito engage the knurled surface of the collar 32, which collar may thengbe ro,- tated :inreithendirectionwto move the 'collet 122 axially-sof as'zttoigeffect-acontraction or expansion of the'cnllet ifazwsi It'willsbefapparentfromfthe foregoing that mlyzimproved :collet chuckithercollet fis keyed to the 'chuck bodvamdz, while it is, movable axially relative thereto, it must V'rotate -witnfther-chucle bodm Additionally, Athe :spring 3l Whichfbears against. tlie:.:coliarf32 fsecuresthe1said-collar in a position 'of adjustment and-any liability ,of accidentalf'displacementfof .thecolletfrom a position oiadustmen-t-istliereby'prevented.

' It willalscibefapparentfthat:should an adjust- 4 ment of the collet be required the same may be effected as by inserting a pointed tool into a slot in the body to manipulateV the collar, thereby avoiding the necessity for disassembling the chuck or demounting the same from the driving Y spindle or shaft. Y

I claim: Y v In a collet chuck the combination of y a chuck bodyf for attachment to a driving spindle, a co1- let mounted' in said body, means to prevent rotation of the collet relative to the body, a collar rotatable in said body threaded onto one end of -thecollet cooperating means on the body and on Y the other end of the collet effective to contract ;thecclletwhenthelatter is moved inwardly with relation-totthebodv'an axially movable sleeve .fincludingcanrinternal cam surface mounted on said body, levers fulcrumed in the body, said leversl cooperating with the internal cam surface and with the collar to move the sleeve inwardly relative :tos :thei fand @the .',bozdy :and sleeve having aligned openings to admit access mathe l collarfffor adjustmgnthe :collar ori.rthefcollet.` c

BERTDLEDENZLER Y REFERENcEs Y"cI'rED Theffollowingreferences are Voffrecord in the file of 'this patentz 

